Hello, first post here. I'm a rank amateur gardener, and I'm looking for a place to read things, and seek advice at times. Thought I'd try here :-) I have 4 Chamaecyparis Obtusa Marble Mountain, 2 in the ground, 2 still in pots. I got them about 2 years ago, quite small, and they have been slowly growing. Over the last, ahh, maybe 6 months or more, 2 of them have developed a relatively fast growing branch, or shoot, or something. It so far doesn't look like the rest of the plant. Is this part of a normal growth pattern?
Probably grafted onto seedlings of the parental species. Otherwise these normal (for the wild species) habit shoots are reversions. In either case they need to be snipped out.
I agree that on your pictures it looks like the different shoots are coming from the rootstock, rather than being reversions manifesting sometimes on unstable cultivars. In either case they have to be removed, unless you like the unusual look of your plants. You can simply prune the shoots coming from the rootstock. With reversions it is slightly different story: how to remove reversions
I'm not a scientist, so this is a layman's explanation. A chimera is a cell that is different in some way from the cell that it divided from that then continues to subdivide into the new, different form. The change in the DNA can be a broken connection , an extra connection, a normally inactive gene made active or a normally active gene turned inactive, or something like that: a change in DNA. It can be due to exposure to chemicals or environmental conditions or radiation, or who knows what. Chimeras have one or more DNA segments different from the rest of the plant. Witches Brooms are an example. What you have is a witches broom that could be propagated a variety of ways: air layer or rooting cuttings or ground layering, etc. It may look like the original Chamaecyparis that obtusa 'Marble Mountain' sported from or was hybridized from, but more likely would not have DNA identical to the original. Plants change, but don't actually "revert". Meristem plants like Hosta have sports that have their own roots and are therefore easier to propagate. This may or may not be the mechanism that is evolution. Unstable DNA gives us thousands of varieties of Hosta and Japanese maple, ad infinitum. IMHO, the more hybridizing that occurs within a species, the more unstable the DNA is resulting in more spontaneous chimeras. If that different growth on your plant was attractive and unique in color or form you could propagate it and name it after your wife and make millions of dollars. Or, not.
These shoots are those of the wild parental species, like one would see visiting the species in its habitat or would get raising a bunch of Hinoki seedlings. Horticultural variants dominate in cultivation because gardeners find these more attractive.
